This is a simple stock space shuttle with working OMS and other accurate flight characteristics. Aim a little towards the East at launch and the boosters will lean you towards 45 degrees as they burn out. Separate boosters and burn through main tank to 100km or below apoapsis. Use OMS for orbital insertion, maneuvering, and reentry. Seats two kerbals.
Video: https://www.youtube.com/watch?v=_6qppUH_bYg&list=UUJFM4-RoT2vlazbATc8eDEw